The β-carotene biofortified transgenic soybean was developed recently through Agrobacterium -mediated transformation using the recombinant PAC (Phytoene synthase-2A-Carotene desaturase) gene in Korean soybean (Glycine max L. cv. Kwangan). GM crops prior to use as food or release into the environment required risk assessments to environment and human health in Korea. Generally, transgenic plants containing a copy of T-DNA were used for stable expression of desirable trait gene in risk assessments. Also, information about integration site of T-DNA can be used to test the hypothesis that the inserted DNA does not trigger production of unintended transgenic proteins, or disrupt plant genes, which may cause the transgenic crop to be harmful. As these reasons, we selected four transgenic soybean lines expressing carotenoid biosynthesis genes with a copy of T-DNA by using Southern blot analysis, and analyzed the integration sites of their T-DNA by using flanking sequence analysis. The results showed that, T-DNA of three transgenic soybean lines (7-1-1-1, 9-1-2, 10-10-1) was inserted within intergenic region of the soybean chromosome, while T-DNA of a transgenic soybean line (10-19-1) located exon region of chromosome 13. This data of integration site and flanking sequences is useful for the biosafety assessment and for the identification of the β-carotene biofortified transgenic soybean.

The β-carotene biofortified transgenic soybean was developed recently through Agrobacterium-mediated transformation using the recombinant PAC (Phytoene synthase-2A-Carotene desaturase) gene in Korean soybean (Glycine max L. cv. Kwangan). GM crops prior to use as food or release into the environment required risk assessments to environment and human health in Korea. Generally, transgenic plants containing a copy of T-DNA were used for stable expression of desirable trait gene in risk assessments. Also, information about integration site of T-DNA can be used to test the hypothesis that the inserted DNA does not trigger production of unintended transgenic proteins, or disrupt plant genes, which may cause the transgenic crop to be harmful. As these reasons, we selected four transgenic soybean lines expressing carotenoid biosynthesis genes with a copy of T-DNA by using Southern blot analysis, and analyzed the integration sites of their T-DNA by using flanking sequence analysis. The results showed that, T-DNA of three transgenic soybean lines (7-1-1-1, 9-1-2, 10-10-1) was inserted within intergenic region of the soybean chromosome, while T-DNA of a transgenic soybean line (10-19-1) located exon region of chromosome 13. This data of integration site and flanking sequences is useful for the biosafety assessment and for the identification of the β-carotene biofortified transgenic soybean.

We isolated low temperature inducible genes using suppression subtractive hybridization (SSH) method and were able to obtain to cloneMLT107 gene encoding peroxiredoxin and aminotransferase. The full-length cDNA of MLT107 is 1,049 bp with an open reading frame (ORF) consisting of 261 amino acid (aa). Genomic southern blot confirmed that mungbean genome has two copies of MLT107 gene. Northern blot analysis was also carried out for the gene expression during ABA, NaCl, drought, wounding and H2O2 stresses. The expression of MLT107 gene significantly decreased by ABA, NaCl and drought stress, but wounding and H2O2 stress significantly induced MLT107 gene expression. Especially, H2O2 strongly induced the MLT107 gene expression. The expression of MLT107gene during low temperature stress started to increase in 3 h after treatment, and than slightly decreased and again increased at 24 h. Using GFP fusion vector, smGFP-MLT107 was targeted both to mitochondria and chloroplast. However, it was mostly targeted to mitochondria and partially targeted to chloroplast. For the functional analysis of MLT107, MLT107 recombinant protein was heterologously expressed in E.coli. The MLT107 recombinant cells showed enhanced antioxidant activity compared to that of vector control cells.